Hydraulic machine

ABSTRACT

The hydraulic machine comprises a turbine and a pump both shaped for the same direction of rotation. The turbine wheel and the pump wheel are keyed on a common shaft with their respective draft tubes disposed in opposite directions. A single spiral casing is connected to the distributor of the turbine and to the diffuser of the pump. Separating means are provided for separating the space in the spiral casing from the space in which the turbine rotates respectively from the space in which the pump rotates. The turbine wheel and the pump wheel are spaced from one another on the common shaft, one of these wheels being arranged substanially in the middle plane of the casing, the latter being connected to the other wheel by conduits for reversing the direction of the tangential component of flow of water the between the spiral casing and said other wheel.

United States Patent [191 Fauconnet July 29, 1975 HYDRAULIC MACHINE [75] Inventor: Michel Fauconnet, Geneva,

Switzerland [22] Filed: Dec. 5, 1973 [21] Appl. No.: 421,789

[30] Foreign Application Priority Data Dec. 14, 1972 Switzerland 18191/72 [52] US. Cl. 415/95; 4l5/l98; 415/500', 60/330 [51] Int. Cl. F03!) 3/10 [58] Field of Search 60/325, 330, 339; 415/500, 415/95, 199 A, 198; 417/405, 406, 407, 409

[56] References Cited UNITED STATES PATENTS 2,996,995 8/1961 Culaud 415/500 X FOREIGN PATENTS OR APPLICATIONS 1,503,243 5/1969 Germany 415/500 Primary Examiner-Edgar W. Geoghegan Attorney, Agent, or Firm-Emory L. Groff, Jr.

[5 7] ABSTRACT The hydraulic machine comprises a turbine and a pump both shaped for the same direction of rotation. The turbine wheel and the pump wheel are keyed on a common shaft with their respective draft tubes disposed in opposite directions. A single spiral casing is connected to the distributor of the turbine and to the diffuser of the pump. Separating means are provided for separating the space in the spiral casing from the space in which the turbine rotates respectively from the space in which the pump rotates. The turbine wheel and the pump wheel are spaced from one another on the common shaft, one of these wheels being arranged substanially in the middle plane of the casing, the latter being connected to the other wheel by conduits for reversing the direction of the tangential component of flow of water the between the spiral casing and said other wheel.

6 Claims, 6 Drawing Figures PATENTEDJULZQ I975 SHEET HYDRAULIC MACHINE The invention relates to a hydraulic machine for transferring power by pumping and turbine operation. Such a machine, known under the name of Isogyre (trademark), associates a hydraulic turbine and a pump in the form of a compact unit having a single spiral casing. The wheels of the turbine and of the pump are keyed on the same shaft with their draft tubes oriented in opposition. The shaping of the blading of these wheels is formed for a same direction of rotation for turbine operation and for pumping. The single direction of rotation of such a machine is rendered possible, in spite of the use of a single spiral casing, by reversal of the direction of the tangential component of the flow of the water in the spiral casing, which inversion is caused either between the spiral casing and the turbine wheel, or between the pump wheel and the spiral casmg. I

This known machine comprises also features (sleeve valves, for example) enabling separation of the internal space of the spiral casing from the space in which the pump wheel rotates, respectively from that in which the turbine wheel rotates. It is thus possible to uncover the pump wheel during turbine operation and to uncover the turbine wheel during pumping operation, in order to avoid losses of power by bubbling.

In machines of this type designed or manufactured hitherto, the neighboring wheels of the pump and of the turbine are arranged in substantially symmetrical manner with respect to the middle plane of the spiral casing and placed as close as possible to this plane. The hydraulic conduits connecting the spiral casing to the turbine wheel, on one hand, and the pump wheel to the spiral casing, on the other hand, are housed in the annular space bounded by the periphery of these wheels and the outer face of the spiral casing surrounding them. Inversion of the direction of the tangential component of flow of the water in the spiral casing is caused in this annular space, either by bending the cross members of the front distributor of the turbine, or by curving the outlet conduits of the pump diffusers.

It is an object of the invention to provide a hydraulic machine comprising a turbine and a pump both designed for the same direction of rotation, the turbine wheel and the pump wheel being keyed on a common shaft with their draft tubes oriented in opposition, a single spiral casing connected, on one hand, to the distributor of the turbine and, on the other hand, to the diffuser of the pump and means enabling separation of the internal space of the spiral casing from the space in which the turbine rotates, respectively from the space in which the pump rotates.

This machine is characterized in that the turbine wheel and the pump wheel are widely spaced from one another on the common shaft, one of said wheels being arranged substantially in the middle plane of the spiral casing, the latter being connected to the other wheel by conduits shaped so as to reverse the direction of the tangential component of flow of water the between the spiral casing and the said other wheel.

The accompanying drawing shows, diagrammatically and by way of example, one embodiment of the hydraulic machine according to the invention, and three modifications, not to be regarded as in any way limiting.

FIG. 1 thereof is a view in axial section.

FIG. 2 is a view in transverse section respectively along lines II--II, IIIIII and IV-IV of FIG. 1.

FIG. 3 is a view in axial section of the first modification.

FIG. 4 is a view in axial section of the second modification.

FIG. 5 is a view in cross-section along the line V-V of FIG. 4.

FIG. 6 is a partial view similar to FIG. 5 of the third modification.

The machine shown in FIG. 1 comprises a single spiral casing 12, a one stage turbine and a one state pump. The turbine wheel 15 and the pump wheel 23 are keyed on a common vertical shaft 13, with their respective draft tubes 14, 24 opening in opposite directions to one another. The blades of these wheels are aligned for the same direction of rotation.

The turbine wheel 15 is located in substantially the middle plane of the spiral casing 12. The hydraulic conduit supplying the turbine wheel 15 is entirely housed in the annular space bounded by the periphery of this wheel and the outer face of the spiral casing surrounding it. The direction of the tangential fiow of water in the spiral casing remains unchanged all along this conduit (see FIG. 2, section IIII).

The cross members of the front distributor 4 of the turbine are formed according to the criteria applied to Francis turbines. It is the same for the guide blades 5 constituting together the movable distributor of the turbine. This distributor is actuated by the usual mechanism, composed of a gating disk 11 acting through a system of link rods 1 on pivots 2 of the guide blades 5.

An obturator 3 of the sleeve valve type, enables the separation of the inner space of the spiral casing 12 from the inner space in which the turbine wheel 15 rotates. The movable guide blades 5 of the distributor could, of course, fulfill the same function. The obturator 3 is inserted between the front distributor 4 and the guide blades 5; it could also be between the guide blades 5 and the turbine wheel 15.

The pump wheel 23 is widely spaced axially with respect to the middle plane of the spiral casing 12.

A fixed element 16 of the frame, carrying the bearing 19 of shaft 13, is inserted between said wheels 15, 23. Reverse conduits 7 ensuring hydraulic connection between the pump wheel 23 and .the spiral casing 12 are provided at the periphery of the fixed element 16 of the frame. The cross members 8 of this element 16 form the lateral walls of the reversing conduits 7 (FIG. 2).

Various annular chambers 17, 20 surrounding the shaft are provided in the fixed element 16, on each side of the bearing and are connected with the outside through channels 18, 21 passing within the thickness of the cross members 8 of the fixed element.

This assembly of annular chambers 17, 20 ensures various functions such as the circulation of oil for the bearing, removal of hydraulic leaks from the wheel joints, aeration, cooling or uncovering" of one of the wheels 15, 23.

The pump wheel 23 is mounted overhanging at the end of the common shaft 13. Its draft tube 24, entirely freed, is hence operating under the most favorable of hydraulic conditions.

The fixer diffuser 9 of the pump, provided with the usual finned device (see FIG. 2, section IIIIII), is located at the periphery of the pump wheel. It does not modify direction of the tangential component of the flow of the water impelled by the pump wheel 23. Its shape and its connection with the reversing conduits are determined by techniques applied to return channels of multi-stage pumps.

The reversing conduits 7 in which the diffuser 9 of the pump opens ensure hydraulic connection and progressive reversal of the direction of the tangential component of flow of water the between the periphery of the pump wheel 23 and the spiral casing 12. They open into this spiral casing at 6 at an angle imposing on the flow of water in coming from the reversing conduit 7 an orientation close to that of the flow of water in the spiral casing 12 (see FIG. 2, section IVIV).

An obturator of the sleeve valve type is inserted between the periphery of the pump wheel 23 and its diffuser 9 and enables the separation of the internal space of the spiral casing 12 from the space in which the pump wheel 23 rotates.

The operation of the hydraulic machine shown in FIGS. 1 and 2 of the drawings is as follows:

When the machine functions as a turbine, the sleeve valve 10 is closed and water is provided into spiral casing 12 from a pipe under pressure in the direction of arrow A (FIG. 2). Said incoming water is directed onto the turbine wheel through its front distributor 4 and between guide blades 5, thus driving common shaft 13 in direction of arrow B.

Thus the common shaft 13 may drive a generator to produce electricity.

When the machine is to operate as a pump the generator is supplied with current and operates as a motor, driving common shaft 13 in the direction of arrow B. Sleeve valve 3 is closed and sleeve valve 10 opened. Thus water is pumped in direction of arrow C (FIG. 1) and discharged by pump wheel 23 through its diffuser 9 and reversing conduits 7 into spiral casing 12. Therefrom the water is directed into a reservoir at a higher level through the above mentioned pipe under pressure.

When either sleeve valve 10 of the pump or sleeve valve 3 of the turbine is closed, the water contained in the space in which either the pump wheel 23 or the turbine wheel 15 rotates may be removed, for example, by means of compressed air.

Numerous modifications of the embodiment described and shown in FIGS. 1 and 2 may be considered.

In the modification shown in FIG. 3, the reversing conduits open in another portion of the outer surface of the wall of the spiral casing 12. These reversing conduits may be include several separate pipes 22. In this case, the passages 18, 21 are provided at the most appropriate places of element 16 whose cross members no longer necessarily constitute the lateral walls of the reversing conduits.

In the embodiment shown in FIG. 4, the reversing conduits are constituted by several separate pipes 22, arranged outside the element 16, with which they have no direct connections.

These pipes 22 are connected at 6 on the outer peripheral surface of the spiral casing 12, at an angle imposing on the flow of water an orientation close to of that of the flow of water in the tank. They could also be connected on another part of the wall of the spiral casing.

The views in cross-section of this modification, shown in FIG. 5, show the hydraulic shaping of the pump and of the turbine.

The left-hand portion of this figure shows the partial volutes 25, arranged at the periphery of the pump wheel 23 and each extended by a divergent tube 26 forming a diffuser and supplying a reversing pipe 22.

In the modification shown in FIG. 6, the partial volutes 25 are arranged at the periphery of a fixed fin diffuser 9. The tubes 26 could also be of constant crosssection.

The slide valve 10 could be replaced by individual obturators provided in each of the separate pipes referred to in the above mentioned two modifications.

Furthermore instead of opening at 6 on the outer periphery of spiral casing 12, the pipes 22 could be connected directly with the high pressure hydraulic conduit, thus avoiding the passage of the pumped water through spiral casing 12 towards said high pressure hydraulic conduit.

This is of special advantage in large hydraulic machines connected to high pressure hydraulic conduits of a diameter exceeding two meters and providing a water column exceeding 60 meters.

In such large and high power equipment it is preferable to connect both the diffuser 9 of the pump and the distributor 5 of the turbine directly with the high pressure hydraulic conduit by means of several pipes.

Such smaller pipes may be provided with individual valves and connected to divergent tubes 26 forming an extension of the partial volutes 25 surrounding both the turbine wheel 15 and the pump wheel 23 (see FIG. 5).

The shaft of the machine may be vertical, horizontal or oblique. The wheel 15 of the turbine and/or of the pump 23 may be radial, diagonal or axial.

The pump may be a two-stage pump with its rotor over-hanging, the turbine being a one stage or two stage turbine. The shaft may just as well be of the traversing type (in the manner of that of a double Francis), the turbine and pump being able to include one or several stages.

The pump may be equipped with orientable diffusers. The position, with respect to the middle plane of the spiral case, of the turbine and pump wheels can be as described on inverted.

Among the considerable technical and economical advantages which are offered by the turbine-pump advantages of the above turbine-pump, described, the following should be particularly mentioned:

The reversal of the direction of the tangential component of the flow of water happens gradually and causes little loss of power in the reversing conduits. This reversal can, for this reason, be caused between the outlet from the diffusers of the pump and the tank. This was excluded with the lsogyre" machines of the prior art. Whatever the form given to the bent diffusers, the secondary flows generated by the curving of the liquid streams caused a lifting of the liquid flow which was slowed down in the diffuser, thus causing considerable power losses.

All the elements of the turbine incorporated in the hydraulic machine described are shaped and act like those of a corresponding conventional turbine. The additional power losses occurring with the prior arrangement by the bent cross members of the turbine are eliminated, the yields in turbine operation are improved, without prejudice to those of pumping operation.

In the Isogyre machines of the prior art, the additional power losses due to the secondary flows formed in the bent cross members of the turbine were maintained within acceptable limits by causing, on the passage of the latter, an acceleration obtained by widely enlarging the spiral casing. In the machine described, however, the outline of the cross members conforms to the criteria normally applied to Francis turbines, thus taking advantage of the experience already acquired to achieve a minimum power losses, while using a smaller spiral casing.

Optimum yields are thus ensured, as well as savings of material and reductions in the bulk of the hydroelectric units which leads to reductions in plant size and engineering costs.

In exceptional cases for which the economic importance of the pumping exceeds that of turbine operation, it is possible to further improve the yield of the pump (to the slight detriment of that of the turbine), by permutation of the location of the pump and turbine wheels with respect to the middle plane of the spiral casing. The diffusers of the pump are thus directly connected to the spiral casing so as to take advantage of the experience acquired to achieve optimum performance. The gradual reversal of the tangential components of the flow of water is then provided by reversing conduits connecting the spiral casing to the distributor of the turbine.

The presence of a guiding bearing between the rotors of the turbine and of the pump presents obvious constructional advantages, and also produces favorable hydraulic effects. The critical numbers of turns of the shaft are more easily avoided without it being necessary to increase its diameter beyond the values required by the torque to be transmitted; the shaft is hence less expensive. The play at the hydraulic joints of the wheels may be reduced, an out of round in operation of the latter no longer being troublesome, the leakages are reduced to the advantage of the yields.

The overhanging of the rotor of the pump frees fully the draft tube of the pump to the advantage of the resistance to cavitation of its wheel. Thus for identical loads, the erosion due to cavitation is reduced; for identical erosion risk a reduced load of the machine may be accepted. A reduction in operating costs or in engineering costs is thus achieved.

In Isogyre machines of the prior art, the common hydraulic joint inserted between the turbine and pump wheels did not permit optimum balancing of the axial thrusts at all rates of operation. In the machine described, the corresponding joints may be individually dimensioned for each wheel and the axial thrusts can be maintained at much lower values.

The removal of leakages of water from the hydraulic joints of the wheels was effected up to now by passages drilled in a central sole plate located between the neighboring pump wheel and turbine wheel. These passages then had to be extended through the cross members of the spiral casing casing. Providing such passages by machining was difficult and expensive. In the machine described, the chambers collecting these leakages, provided in the support of the bearing and the evacuation ducts therefore are cheaper to manufacture.

Moreover, such evacuation ducts become shorter and more direct, so that the removal of leakages is facilitated.

I claim:

1. In a hydraulic machine, including a frame, a fixed element on said frame, a turbine and a pump each including a wheel, said turbine and pump both shaped for rotation in the same direction, a vertical shaft, said turbine wheel and the pump wheel each connected to said shaft, said turbine including a distributor, said pump including a diffuser, said turbine and pump each including a draft tube, said draft tubes disposed in opposite directions to one another, a single spiral casing connected to the distributor of the turbine and to the diffuser of the pump, valve means permitting the selective separation of the internal space of the spiral casing from the space in which the turbine rotates and the space in which the pump rotates, a bearing for said vertical shaft, said bearing mounted on said fixed element of said frame and disposed between the turbine wheel and the pump wheel whereby only one of said wheels is disposed substantially in the central plane of said spiral casing and the other said wheel is thus spaced apart from said one wheel, direct conduits connecting said spiral casing to said one wheel and reversing conduits longer than said direct conduits connecting said spiral casing to the other wheel for progressive reversal of the direction of the tangential component of flow of the water between the spiral casing and said other wheel, or vice versa.

2. A hydraulic machine according to claim 1 wherein a plurality of annular chambers surround the vertical shaft and are housed in the fixed element of the frame, a plurality of channels connecting said chambers with the outside.

3. A hydraulic machine according to claim 1 wherein said reversing conduits are formed in the fixed element of the frame.

4. A hydraulic machine according to claim 1 wherein said reversing conduits comprise separate pipes housed in the fixed element of the frame.

5. A hydraulic machine according to claim 1 wherein the said one wheel disposed substantially in the central plane of the spiral casing in the turbine wheel, the pump wheel being axially spaced from this plane and the reversing conduits, connecting the outlet of the diffuser of the pump to the spiral casing, being provided substantially outside the annular space defined by the periphery of the turbine wheel and the outer face of the spiral casing surrounding it.

6. A hydraulic machine according to claim 1 wherein the said one wheel disposed substantially in the central plane of the spiral casing is the pump wheel, the turbine wheel being axially spaced from this plane and the reversing conduits, connecting the inlet of the distributor of the turbine to the spiral casing, being provided substantially outside the annular space defined by the periphery of the pump wheel and the outer face of the spiral casing surrounding it. 

1. In a hydraulic machine, including a frame, a fixed element on said frame, a turbine and a pump each including a wheel, said turbine and pump both shaped for rotation in the same direction, a vertical shaft, said turbine wheel and the pump wheel each connected to said shaft, said turbine including a distributor, said pump including a diffuser, said turbine and pump each including a draft tube, said draft tubes disposed in opposite directions to one another, a single spiral casing connected to the distributor of the turbine and to the diffuser of the pump, valve means permitting the selective separation of the internal space of the spiral casing from the space in which the turbine rotates and the space in which the pump rotates, a bearing for said vertical shaft, said bearing mounted on said fixed element of said frame and disposed between the turbine wheel and the pump wheel whereby only one of said wheels is disposed substantially in the central plane of said spiral casing and the other said wheel is thus spaced apart from said one wheel, direct conduits connecting said spiral casing to said one wheel and reversing conduits longer than said direct conduits connecting said spiral casing to the other wheel for progressive reversal of the direction of the tangential component of flow of the water between the spiral casing and said other wheel, or vice versa.
 2. A hydraulic machine according to claim 1 wherein a plurality of annular chambers surround the vertical shaft and are housed in the fixed element of the frame, a plurality of channels connecting said chambers with the outside.
 3. A hydraulic machine according to claim 1 wherein said reversing conduits are formed in the fixed element of the frame.
 4. A hydraulic machine according to claim 1 wherein said reversing conduits comprise separate pipes housed in the fixed element of the frame.
 5. A hydraulic machine according to claim 1 wherein the said one wheel disposed substantially in the central plane of the spiral casing in the turbIne wheel, the pump wheel being axially spaced from this plane and the reversing conduits, connecting the outlet of the diffuser of the pump to the spiral casing, being provided substantially outside the annular space defined by the periphery of the turbine wheel and the outer face of the spiral casing surrounding it.
 6. A hydraulic machine according to claim 1 wherein the said one wheel disposed substantially in the central plane of the spiral casing is the pump wheel, the turbine wheel being axially spaced from this plane and the reversing conduits, connecting the inlet of the distributor of the turbine to the spiral casing, being provided substantially outside the annular space defined by the periphery of the pump wheel and the outer face of the spiral casing surrounding it. 